Class 4 Social Studies Chapter 12 Question Answers

Class 4 Social Studies Chapter 13 Question Answers cover book exercise questions in a simplified and precise way. Class 4 Social Studies Chapter 13 Question Answers are easy to understand and learn for exams.
#Our Water Wealth

Class 4 Social Studies Chapter 12 Question Answers

A. Fill in the blanks.

1. Tube wells use pumps run by electricity or diesel.
2. A structure made to hold back the water of a river is called a dam.
3. Electricity made using the force of water is called hydroelectricity.
4. Irrigation canals take river water to areas of water shortage.

B. Answer the following questions.

1. Why can seawater not be used for drinking or irrigation?
Answer: Because Seawater is salty.

2. What problems occur in India because of rains occurring only in the monsoon months?
Answer: Rivers and other water sources dry up in hot summers and people face water problems.

3. Why are dams called multipurpose projects?
Answer: Dams are useful in many ways. Dams hold water. This water can be used for drinking, irrigation, and generating hydroelectricity. Hence, dams are called multipurpose projects.

4. What is hydroelectricity?
Answer: Electricity generated from the force of water is called hydroelectricity.

5. Several environmentalists are opposed to large dams. Why?
Answer: Environmentalists claim that large dams –
– cause environmental problems
– displace people living in the reservoir area.
– destroy plant and animal life in the area.
– cause earthquakes in some areas.

6. How are irrigation canals useful?
Answer: Irrigation canals take water from rivers where there is a shortage of water.

7. What do you mean by rainwater harvesting?
Answer: Rainwater harvesting is the collection of rainwater. This water is allowed to flow into the ground to increase the groundwater level.

C. Multiple choice questions.

We need water for
(A) drinking
(B) washing
(C) cooking
(D) all of these
Which of these are big dams built across major rivers in India?
(A) Bhakra Nangal
(B) Nagararjunasagar
(C) Hirakund
(D) all of these
Irrigation canals mostly take water from which source?
(A) sea
(B) wells
(C) rain
(D) rivers
Which of these best describes rainwater harvesting?
(A) harvesting crops during the rainy season
(B) storing rainwater for later use
(C) using rainwater to generate electricity
(D) using rainwater to fill reservoirs built on rivers
Dams built on rivers are useful in
(A) preventing floods
(B) irrigation
(C) producing electricity
(D) all of these